Automatic coupling system for freight cars

ABSTRACT

An improvement in an automatic coupling system for a railway car which is equipped with a mechanical coupler, a main air line adapted to be connected to a corresponding air line of another railway car, a main valve interposed in the main air line, and means for actuating the main valve responsive to intentional coupling of the railway car. The improvement, in its preferred form, takes the form of a pair of pilot-operated check valves connected in parallel to the air conduit supplying the actuating means to prevent flow of air therethrough when the main air line is charged but uncoupled at one end, and to maintain the flow therethrough when coupled to another car but with either car having a faulty interface valve actuation which would normally allow the main valve to close.

United States Patent Cope [S4] AUTOMATIC COUPLING SYSTEM FOR FREIGHT CARS [72] Inventor:

[ 7 3 Assignee:

[22] Filed:

[21] Appl. No.:

May 12, 1971 Geoffrey Wilton Cope, Williamsville, NY.

Dresser Industries, Inc., Dallas, Tex.

References Cited 1/1971 l/l97l 8/1971 8/1971 Cope ..213/76 Swamidas ..213/76 Dwyer, Jr. ..213/76 Cope ..213/76 UNITED STATES PATENTS 51 Oct. 10,1972

Primary ExaminerDrayton E. Hoffman Attorney-Robert W. Mayer, Thomas P. Hubbard, Jr., Daniel Rubin, Raymond T. Majesko, Roy L. Van Winkle, William E. Johnson, Jr., Eddie E. Scott and Morgan L. Crow ABSTRACT An improvement in an automatic coupling system for a railway car which is equipped with a mechanical coupler, a main air line adapted to be connected to a corresponding air line of another railway car, a main valve interposed in the main air line, and means for actuating the main valve responsive to intentional coupling of the railway car. The improvement, in its preferred form, takes the form of a pair of pilotoperated check valves connected in parallel to the air conduit supplying the actuating means to prevent flow of air therethrough when the main air line is charged but uncoupled at one end, and to maintain the flow therethrough when coupled to another car but with either car having a faulty interface valve actuation which would normally allow the main valve to close.

PATENTED E 3.696.941

sum 1 0F 2 FIG. I

INVENTOR GEOFFREY W. COPE PATENTED 0U 10 I972 SHEET 2 [1F 2 FIG. 2

INVENTOR GEOFFREY W. COPE ATTORNEYS AUTOMATIC COUPLING SYSTEM FOR FREIGHT CARS In order to comply with the regulations of the A.A.R. and Interstate Commerce Commission, railway cars are interconnected, when coupled, by an air line which serves to operate air brakes with which each of the cars is equipped. The air brakes are designed to be applied when the airline is vented and be released when the air line is pressurized, thus providing for automatic application of the brakes of the car in the event of an accidental or unintentional separation of the railway cars resulting in a break in the air line. Accordingly, when railway cars are to be intentionally separated, the air line at both ends of the car should be closed to enable the brakes of the cars remaining coupled to the locomotive to be controlled and the uncoupled cars to retain their mobility for humping or other purposes.

Recently, as disclosed in United States Letters Patent No. 3,556,314, assigned to the present assignee,an au tomatic pneumatic coupling system for railway cars is described, which may be used in connection with standard A.A.R. knuckle-type couplers, for automatically controlling the valving of the air lineof a railway car. The automatic pneumatic coupling system of the above patent differentiates between intentional and ac-' cidental uncoupling. Upon intentional uncoupling, the pneumatic system closes the air line, preserving pressure in the brake system so that the railway car may retain its mobility. Upon accidental uncoupling, the air line remains open, thus bleeding the brake system of air pressure and effecting application of the brakes.

Generally, when cars remain standing in a yard or siding for a considerable length of time, they are coupled and all of the air is bled off. When needed, the cars are manually uncoupled and separated. When this occurs, the main valve actuating means or control valve in the pneumatic coupling system will remain open since it is generally detented and requires pilot air pressure to close it. If the car is then coupled at one end to a pressurized car, the free or uncoupled end of the car will discharge air into the atmosphere because of the open main control valve which will readmit air to the main brake line valve and shift the valve to the coupled or open position.

Accordingly, it is among the objects of the present invention to provide a means for preventing the venting of air to the atmosphere on a railway car that is charged through coupling at one end but remains uncoupled at the other end.

It is another object of the invention to provide a means for insuring the maintenance of air pressure in the brake line valve of a railway car in the event that a failure occurs in the puffer cylinder system while the car is in operation and still coupled.

A further object is to provide a means for preventing the bleeding of the brake air line during an abortive coupling of railway cars.

The foregoing and other objects and features of the invention will be apparent hereinafter in the detailed description and drawings, in which:

FIG. 1 is a schematic view of an automatic pneumatic coupling system of the prior art; and

FIG. 2 is a schematic view of a modified automatic pneumatic coupling system, in a preferred embodiment, according to the present invention.

In accordance with the present invention, there is provided an automatic coupling system for a railway car. In the system there is a main air line adapted to be connected to a corresponding air line of another railway car for communicating air between the cars. A main valve is interposed in the main air line for controlling the flow of air through the line. A main valve actuating means responsive to mechanical coupling of the railway car to a similarly equipped car controls the flow of air to the main valve. The combined action of a low pressure cylinder or puffer and valve means opens the actuating means to enable air from air conduit means to pass through the actuating means. To prevent inadvertent venting of the air when one end is not coupled to another railway car when the main line is charged, and after it has been uncoupled while in an uncharged condition, valve means are connected to the air conduit means between the main valve actuating means and main air line.

In FIG. 1, the main air line 40 which is adapted to receive air from an adjoining railway car for supplying air to a brake system, has interposed therein a main air line valve 41. Valve 41 is a two-way valve, which normally is maintained in a closed position by spring 42 acting against head 43, may be opened by air pressure exerted against head 39 from control line 77.

In order to open valve 41 when the railway car equipped with the pneumatic circuit of FIG. 1 is actuated by the cars being coupled and to maintain it open when it becomes unintentionally uncoupled and also to permit closing of valve 41 upon intentional uncoupling of the railway car, main valve actuating means are provided. The main valve actuating means includes valves 45-47 and cylinder 48 connected by pneumatic control lines hereinafter described. Valves 45, 46 and 47 serve to direct air derived from the main air line 40 through control lines 49 and 51. Lines 49 and 51 are provided with spring biased check valves 50 and 60, respectively. As illustrated, check valves 50 and 60 permit flow from main air line 40 into control lines 49 and 51, but prevent flow in the reverse direction.

Upon the uncoupling of a railway car equipped with the circuit of FIG. 1 with a similarly equipped car, and assuming one or both cars are charged, air will be available in the main air line 40 and the flow through control line 49 and check valve 50 into control line 51. Control line 51 is provided with two branches 52 and 53, the flow through which is controlled by valves 46 and 47, respectively. Valve 46, which controls the flow through line 52, as mentioned above, is a two-way sliding spool valve or fluidic interface valve which upon coupling is moved to the position shown in FIG. 1 by pressure chamber 54 acting on head 55 of the sliding spool 56. Pressure in chamber 54 is derived from valve 48 which is a spring biased'plunger-type valve. Cylinder 48, often referred to as a puffer" cylinder, has a spring 57 which normally urges a plunger 58 to an extended position. Plunger 58 which attaches to cup 59 also serves to support the inner convolution of a rolling diaphragm 61. Diaphragm 61 forms a chamber 62 which communicates with the chamber 54 of valve 46 through a control line 63.

Upon coupling of the railway car equipped with this system, plunger 58 is depressed by engagement with a suitable interfacing surface extending from the adjoining railway car, thereby compressing air in chamber 62. Pressure in chamber 62 will be transmitted through control line 63 to chamber 54, which like chamber 62 is provided with a rolling diaphragm 64. The pressure generated in chamber 54, as explained above, moves the spool 56 of valve 46 to the position illustrated, permitting air introduced through branch 52 of control line 51 to pass through valve 46 and control line 65 attached thereto. The air admitted to control line 65 will act against head 66 of a two-way sliding spool valve 45, causing spool 67 to move to the position shown in FIG. 1, as the opposite control head 68 of spool 67 will have little pressure exerted thereon. Spool 67 will be maintained in the position shown in FIG. 1 by a spring detent 75 until pressure is applied against head 68. On movement of spool 67 to the position shown, air in control line 51 passes through line 76 and valve 45. The air passing through valve 45 will also pass through line 77 which communicates the air with head 39 of valve 41, moving head 39- to the position shown. This opens valve 41 and permits air in main air line 40 which can be supplied by the subject cars in line or from a corresponding air line 40 of an adjoining railway car to pass through valve 41 into the brake train line of the railway car, in either direction, depending upon which of the cars was initially charged.

In the coupling procedure, during which the main air line valve 41 is open to permit a communication between main air line 40 and corresponding main air line 40' of an adjoining car, the valve 47, which is a spring biased sliding spool valve, is maintained in the position shown by spring 78 which acts against head 79 of spool 81. The stem portion 82 of spool 81 in one embodiment is connected through a spring 83 and a pin and slot connection 84 to an operating lever 85 of a conventional coupler operating rod. As is well known to those skilled in the art, by operation of the lever 85, the lock lift assembly of a conventional knuckle-type coupler may be lifted to permit opening of the knuckles when uncoupling the railway car.

Should the railway car become unintentionally uncoupled, due to a broken knuckle or knuckle pin, the plunger 58 of puffer cylinder 48 would extend, decreasing the pressure on head 55 of spool 56, thus permitting spool 56 to move upwardly from the atmospheric air pressure in pilot line 74. In its upward position, valve 46 would block flow through line 52 and permit air pressure on head 66 of valve 45 to be vented through control line 65 and exhaust port 86 of valve 46. However, the detent means 75 of valve 45 will prevent the shifting of spool 67, thus maintaining pressure on head 39 of valve 41. Valve 41 would then remain in the open position permitting venting of the main air line 40. As

main air line 40 will be separated from the corresponding air line 40 of an adjoining car upon an unintentional uncoupled, main air line 40 will vent and the air brakes will be applied. The same action will occur in the adjoining car. The air pressure established in the control lines 49 and 51 will be maintained upon unintentional uncoupling as check valves 50 and 60 will seat upon venting of the main air line 40, preventing loss of pressure in the control lines 49 and 51 downstream from the check valves 50 and 60.

However, upon intentional uncoupling, which is effected by normal operation of the uncoupling lever 85 about its pivot point 87, the spool 81 of valve 47 will be shifted to the right, as viewed in FIG. 1, permitting air in control line 51 to flow through branch 53 thereof and valve 47 into line 88 which communicates with control line 74. Air pressure created in control line 74 through valve 47 will shift valves 45 and 46 and spool 56 will shift opening line 65 to exhaust port 86. This will relieve the pressure on head 66 of valve 45 permitting the pressure on head 68 to overcome the detent and shift spool 67 upward as viewed in FIG. 1. Upon shifting of spool 67, air flow from control line 51 through valve 45 will be blocked, and the air creating pressure on head 39 of valve 41 will be vented by flow through line 77, valve 45 and exhaust port 89 of valve 45. Upon venting of the air from valve 41, spring 42 will effect closing of valve 41 by urging head 43 against seat 91.

Upon separation with railway cars during intentional uncoupling, the mobility of the railway car equipped with the system of FIG. will be maintained as air pressure in the brake system will be maintained by the closing of valve 41. After the operator has released lever which is normally before the cars are separated, valve 47 again returns to the position shown in FIG. 1. With valve 47 returning to its initial position by spring 78, the pressure in line 74 is maintained to hold the valve position until'actual separation of the cars at which time the line 74 pressure will be vented to atmosphere and then the system is again ready for opening of valve 41 upon coupling to railway cars equipped with this system.

With the pneumatic coupling system described above, if the cars were uncoupled as a group and left in a yard for a period of time, the air would normally bleed from or be purposely vented from the system. Thus, when a worker desired to couple one or more cars to air charged cars, several problems would result. The worker would uncouple the uncharged cars by moving the lever 85 as described previously. Valve 41 would be closed by spring 42 when air was removed or bled from the system. However, valves 45 and 46 would remain open since they rely upon pilot air pressure from line 74 to effect a closing. Since air had been bled from the system, pilot air would not be available. When the car is then coupled to a charged railway car and the main train line 40 communicates with the source of air, the air will pass through the coupled end and through the car to the opposite end main control valve 45 which will open the main train line valve 41, and air will be vented to the atmosphere through the uncoupled end of the car.

FIG. 2 illustrates a modification of the basic system which overcomes this shortcoming and others to be mentioned.

More particularly, the fluidic interface valve 46 is provided with an internally mounted spring 98 to return the valve to the closed position when the car is uncoupled and pressure is released from the coupling valve or puffer 34.

A pilot-operated check valve 100 is connected to the input line 76 of the control valve 45. The pilot air to check valve 100 is obtained from output line 65 of the fluidic interface valve 46 by means of pilot air conduit 102. The check valve 100 restricts the flow of air through line 76 to the control valve by means of a poppet 104 which closes the outlet from the check valve. As mentioned previously, when a railway car is coupled on the opposite end to a charged car, air enters the system through conduit 51. With the check valve 100, the air will not pass through the open control valve and thus be eventually vented to the atmosphere. However, when another railway car is added to the end thus coupling both ends of the car in question, the puffer plunger 58 will be depressed and will open the interface valve 46. Air will then pass through valve 46 and thence through conduit 102 to force the piston 106 out of position to depress the poppet 104 and permit the main line air to pass through the check valve exit, the main control valve 45 and then open the main valve 41.

This modification places a great deal of reliance upon the continuous operation of the puffer cylinder 48; and so, a similar check valve 110 is preferably attached in parallel with check valve 100. This check valve obtains its pilot air through conduit 112 which is connected to the main air line 40 between the valve 41 and the end of the car. Therefore, the compression of the puffer cylinder 48 will shift the fluidic interface valve 46, charging the line 102 to check valve 100, unseating the valve and allowing air to pass through the main control valve 45 to the main train line valve pilot line 77 for opening the valve. When the main train line valve 41 opens, the pilot conduit 112 to check valve 110 will be charged with air opening the check valve by movement of the piston 114 and poppet 116 arrangement and allowing air to pass through the main control valve 45. With the check valve 110 open under the influence of the main train line air pressure, the effect of check valve 100 will be eliminated, and a complete loss of air pressure in the puffer cylinder line 63 will have no effect on the condition of the main train line valve 41.

Also included in the system is a flow control mechanism 118 which will be described subsequently. This addition requires that the puffer cylinder 48 must be held in, that is, the plunger 58 must be depressed, for a predetermined length of time before the main control valve 45 is actuated. A quick release of the puffer cylinder plunger 58, as by an abortive coupling attempt, would permit the fluidic interface valve 46 to return to the closed or uncoupled position under the influence of its spring 98, as shown in FIG. 2, before actuation of the main control valve and permit the air pressure up to the flow control valve to exhaust to the atmosphere.

The time delay means 118 takes the form of a manually adjustable needle valve or a fixed orifice choke inserted in conduit 65 and a check valve 120 in parallel leg 122 of the conduit 65.

Thus, upon intentional coupling of a railway car by depression of the puffer cylinder plunger 58 in the manner described above, air communicated through the main train line 40 will pass through conduits 51 and 52 and thence through the interface valve 46 and conduit 65. Due to the resistance created by needle valve 119, a time delay will be developed in the shifting of valve 45. The air thus passing on a delayed basis to the control valve 45 to urge it toward the open position assures that in an abortive coupling attempt, when the plunger 58 of the puffer cylinder 48 would be depressed for only a verly short feriod of time, insufficient air pressure woul be butt up to overcome the valve detent and the spring in the interface valve would close the valve 46 to preclude air from passing therethrough before the actuation of valve 45. The check valve forces air to pass the needle valve and generate the delay in the one direction but unseats to permit quick exhaust of the air from the valve 45 in the intentional uncoupling operation.

It is intended that the foregoing description and drawings be construed as illustrative and not in limitation of the invention.

Having thus described the invention in detail and with sufficient particularity as to enable those skilled in the art to practice it, what is desired to have protected by Letters Patent is set forth in the following claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an automatic coupling system for a railway car which includes a coupler, a main air line adapted to be connected to a corresponding air line of another railway car for communicating air between the cars, a main valve interposed in the main air line for controlling the flow of air therethrough, main valve actu ating means responsive to intentional coupling of the railway car for controlling the flow of air to the main valve, means for opening and closing said actuating means, air conduit means connecting the actuating means to the main air line, the improvement comprising valve means connected to the air conduit means between the actuating means and main air line to prevent control valving from assuming positions that would permit flow of air to atmosphere through a main valve when the main air line is charged at one end and with the other end uncoupled.

2. The system of claim 1, in which the valve means consists of at least one pilot operated check valve.

3. The system of claim 1, in which the valve means consists of two pilot-operated check valves connected in parallel to the air conduit means.

4. The system of claim 3, in which one of the pilot check valves is operated by air from the means for opening the actuating means and the other is operated by air from the main air line between the main valve and coupler.

5. The system of claim 1, in which the means for opening the actuating valve is an air operated valve responsive to a charge from a plunger actuated low pressure cylinder or puffer and contains a mechanical means therewithin to maintain it in the closed position when the railway car is uncoupled.

6. The system of claim 1, in which time delay means is disposed between the means for opening the actuating valve and the actuating valve. 

1. In an automatic coupling system for a railway car which includes a coupler, a main air line adapted to be connected to a corresponding air line of another railway car for communicating air between the cars, a main valve interposed in the main air line for controlling the flow of air therethrough, main valve actuating means responsive to intentional coupling of the railway car for controlling the flow of air to the main valve, means for opening and closing said actuating means, air conduit means connecting the actuating means to the main air line, the improvement comprising valve means connected to the air conduit means between the actuating means and main air line to prevent control valving from assuming positions that would peRmit flow of air to atmosphere through a main valve when the main air line is charged at one end and with the other end uncoupled.
 2. The system of claim 1, in which the valve means consists of at least one pilot operated check valve.
 3. The system of claim 1, in which the valve means consists of two pilot-operated check valves connected in parallel to the air conduit means.
 4. The system of claim 3, in which one of the pilot check valves is operated by air from the means for opening the actuating means and the other is operated by air from the main air line between the main valve and coupler.
 5. The system of claim 1, in which the means for opening the actuating valve is an air operated valve responsive to a charge from a plunger actuated low pressure cylinder or puffer and contains a mechanical means therewithin to maintain it in the closed position when the railway car is uncoupled.
 6. The system of claim 1, in which time delay means is disposed between the means for opening the actuating valve and the actuating valve. 